The Senate Judiciary Committee issued a scathing rebuke Thursday of the U.S. Marshals Service, alleging misconduct and mismanagement at the law enforcement agency, including the widespread practice of using forged subpoenas in order to collect telephone records. The allegations against the enforcement arm of the federal courts, which falls under the purview of the Department of Justice, were outlined in a memo from departing Republican Committee Chairman Sen. Chuck Grassley. The report was the culmination of a nearly four-year investigation that found “a culture of mismanagement, abuse of authority and lax accountability.”

“[The memo] highlights years of alleged misdeeds, from deputy marshals forging hundreds of subpoenas to gather telephone records—a years-long practice that, even when it was discovered, led to no personnel dismissals—to repeated attempts to retaliate against whistleblowers who brought misconduct to light,” the Washington Post reports. “Investigations by Grassley’s committee and the Justice Department’s inspector general found that the marshals’ leadership, including the agency’s former director, Stacia Hylton, violated federal hiring rules in filling positions at the agency and misspent money.”

Supporting documents accompanying the memo found the use of fake subpoenas to gather telephone records was pervasive. Over a 10-year period up until 2005, about 800 bogus subpoenas with the pre-printed signature of a judge were served on telecommunications providers even though the judge whose signature was used says he not only didn’t sign off on the subpoenas, he wasn’t even on the court after 2000 while his signature was still in use. “A review of Marshals Service subpoenas received by AT&T and related companies over less than a year and a half found 134 fraudulent subpoenas out of a total of 162 documents recovered,” according to the Post. “One service employee told investigators that he alone used the phony subpoenas approximately 500 times.”

When the subpoena fraud was uncovered, the leadership at the Marshals Service took essentially no punitive action: No criminal files were filed, a single employee was reprimanded, and two others involved were later given promotions.